Ask the Expert: What is Oral Cancer?

In this edition of Ask the Expert, we talked with two of our experts about oral cancer, including the importance of early detection, it’s connection to our overall health, and how we’re advancing research to improve the diagnosis and treatment of oral cancer.

Over 50,000 Americans will be diagnosed with head & neck cancer this year, causing more than 10,000 deaths, making it the sixth most common cancer in the world. There are more than 640,000 new cases of oral cancer diagnosed annually worldwide. The College of Dentistry will host a free oral cancer screening day on April 18 from 10 a.m. to 12:30 p.m. in Room 129 of the Oral Medicine Clinic, as part of a national Oral Head & Neck Cancer Awareness week.

Dr. Beth Miloro is a Clinical Assistant Professor in the Department of Oral Medicine and Diagnostic Sciences. She teaches dental students and serves as the primary oral medicine specialist in the UIC College of Dentistry's Oral Medicine clinic.

Dr. Joel Schwartz is a professor, Director of Oral Maxillofacial Pathology and oral cancer researcher for forty years while senior scientist at the National Institutes of Health, and internationally recognized cancer centers and in the department of Oral Medicine and Diagnostic Sciences at the UIC College of Dentistry.

Both have specialized training in Oral Pathology.

What is oral cancer and how does it occur?

Dr. Miloro: Oral cancers are malignant lesions or tumors (they can spread to other parts of the body) that are located in the soft tissues of the mouth (lips, gums, tongue, floor of mouth, palate), as well as the jaw bones and salivary glands. Most oral cancers begin in the flat, thin cells (squamous cells) and are termed squamous cell carcinomas.

Mouth cancer occurs when cells on your lips or in your mouth develop changes (mutations) in their DNA. These mutations allow cancer cells to continue growing and dividing. The accumulating abnormal mouth cancer cells can form a tumor. Head and neck cancers are normally diagnosed in individuals at about age 62, but one-quarter of patients are younger than 55-years-old.

Dr. Schwartz: In general, cancers of the throat and oral lining will occur at particular sites because tissues such as the top and bottom surfaces of the tongue have sites of weakness where they form a boundary. The adjoining tissue boundary is composed of cells growing at different rates at each side. A weakness of cell-to-cell attachment occurs at the boundary which increases levels of inflammation, which is caused by contact with microbes that come from the oral environment in our mouth and gain access to deep parts of the tissue. The body in response to inflammation tries to repair this wound or site of weakness with increased cell growth and this exposes the DNA to damage.

Oral cancers are often a product of long-term DNA damage exposures for a decade or more to produce DNA damage from un-healthy products such as tobacco. Health and dietary habits, and exposures to chemicals (like in cigarettes or alcoholic beverages) and microorganisms produce persistent non-repairable DNA that begins to select out cells that survive because their genetics enhance growth. These cells form groups or clones that expand, which leads to growth and spreading of the cancer in the mouth, and even to other parts of the body.

What factors increase my risk of oral cancer?

Dr. Miloro: Several risk factors may increase the chance of oral cancer. Tobacco use and alcohol consumption are risk factors and when used together, the risk is even greater. The use of betel quid or paan, a substance (areca palm nuts, betel leaf, sometimes tobacco leaf) chewed for stimulatory effects, has also been identified as a risk factor. Excessive sun exposure is also a risk factor for lip cancers.

Dr. Schwartz: Recent studies show that infection with certain types of human papillomavirus (HPV) are linked to oropharyngeal (throat) cancer. Human papillomavirus infection is a sexually transmitted disease (STD), and this exposure is a reason young female and males are now recommended to receive a vaccination to reduce risk for cancers later in life as they become sexually active. There are different types of this virus and some are high while others are low risk for cancer but recent evidence also indicates these low risk types are linked to oral cancer risk.

The high-risk type of HPV produces a cancer of the throat (oropharynx) and base of the tongue in increasing numbers of cases and percentage of total number of head and neck cancers. However, these cancers often show a better response to treatment, and survival than other head and neck cancers.

Did you know:

You are 3 times more likely to get oral cancer if you drink or use tobacco. And 30 times more likely if you have HPV, or Human Papillomavirus.

Can I die from oral cancer?

Dr. Schwartz: Unfortunately yes, depending on your risk level. Death rates for oral cancer is highest among males from African American heritage compared to other ethnicities. Recent data also suggests that for some Chicago communities, risk for head and neck cancer is associated with risk for other cancers; such as colorectal (intestine) and lung. Moreover, these cancers can develop among “unlucky” individuals that have biochemical and metabolic disorders that alters cell growth. Effects from these influences reduce repair activity leading to continual presence of DNA damage and increased risk for cancer change.

What symptoms should I be looking for?

Dr. Miloro: Among the symptoms of these cancers are a sore in the mouth that doesn’t heal; pain in the mouth that doesn’t go away; a lump or thickening in the cheek; a white or red patch on the gums, tongue, tonsil or lining of the mouth; and numbness of the tongue or other area of the mouth.

Early stage oral cancers are usually asymptomatic, so you may not feel any symptoms. That is why annual oral cancer exams are so important. It is performed by your dentist as part of a routine dental exam, so keeping up with your routine cleaning and exam is an important part of helping identify precancerous of cancerous lesions early. Early lesions may appear as non-healing red, white or mixed red and white flat lesions. If left untreated, they will progress into an ulcerative tumor, which may become painful. A non-painful lump in the neck that does not go away may be a sign of oral cancer.

Dr. Schwartz: People with higher risk or previous diagnosis should get examined more frequently; the recommendation is every 3-6 months. It is important that head and neck and all oral tissues be examined because of the pattern of growth of pre-cancers and cancers which means a cancer mass is accompanied by a field of changes surrounding the visible tumor that also requires assessment.

How is oral cancer diagnosed?

Dr. Miloro: Oral cancer is diagnosed with a biopsy of the tissue. This can be performed by a dentist, oral pathologist or oral surgeon. The area is numbed, similar to how a tooth is numbed for a filling, and then a small piece of tissue is removed (usually .5cm or less). Resorbable sutures are placed and will fall out on their own in 5-7 days. The tissue specimen is sent to an oral pathologist, a specialist who analyzes the tissue microscopically to determine if cancer cells are present.

Dr. Schwartz: The “gold-standard” today is the examination of a tissue biopsy section by a pathologist. However, this approach is not a 100% accurate and a second biopsy might be required to determine the diagnosis. In addition, large cancers require multiple biopsies to enhance accuracy of diagnosis. We, and others, through funding by the National Science Foundation and National Institutes of Health have developed non-invasive genetic based methods to detect the presence of cancer cells compared to normal cells. This test requires cells from a soft brush. The level of accuracy for this test is about at the level of a pathology tissue section examination.

We use a clinical and pathology based approach that measures size of tumor (T) and number of draining lymph nodes (N) and results in a TNM stage. This is used to identify the category of types of oral cancer, each having its own treatment response based on immunology activity.

What should I do to lessen my risk of oral cancer?

Dr. Miloro: The first line of defense is getting regular dental examinations that include an oral cancer exam. Regular dental examinations help detect oral cancer early, which is critical. In fact, early detection of oral cancer can literally save your life - people with early stage detection have an 80% chance of surviving after 5 years vs. only a 30-40% chance with late stage cancers. Also keep in mind that smoking, tobacco use and alcohol consumption can elevate your risk. Additionally, you can visit the Oral Medicine clinic at UIC , where we specialize in diagnosing oral, head and neck cancers.

Video: Oral Cancer Diagnosis at UIC College of Dentistry

What happens after diagnosis?

Dr. Miloro: Once a biopsy determines a lesion is cancer, further imaging and tests may be needed to assess whether the cancer has spread to other parts of the body. Cancer staging is based on clinical findings such as the size of the tumor, and whether or not it has spread to the lymph nodes or other parts of the body. Staging helps doctors determine the most appropriate treatment.

Dr. Schwartz: Immunotherapy is the use of the immune response to attack cancer cells while not damaging normal cells. While immunotherapy had limited success in the past, recent biotechnology developments have led to new drug therapies, such as antibodies that target the cancer forming process. For instance, targeting checkpoint proteins that helps keep immune cells from attacking other cells in the body increases anti-tumor immune killing capacity. Other approaches to enhance immune reactivity to oral cancer is also on-going by trial studies that increase the recognition of cancer cells compared to normal cells, while other new drugs are attempting to regulate growth factor signals. These new medications are used in combination with the established chemotherapy, radiation and surgery approaches. These new protocols are expected to reduce growth of primary tumor masses, and appearance of new tumors.

The Oral Medicine clinic is staffed by faculty members who have extensive professional expertise and experience in all aspects of Oral Medicine and Clinical Oral Pathology. We are the only academic center of this kind in Chicago.

We use a multidisciplinary approach to expertly diagnose and treat these oral mucosal diseases. The Oral Medicine team collaborates with all dental disciplines, including Periodontics, Endodontics, and Oral Surgery as well as a number of medical disciplines, including ENT, Dermatology, Oncology, Neurology, Hematology, Radiology, Surgery, and Psychiatry.

The University of Illinois at Chicago College of Dentistry is a worldwide leader in oral health education, clinical care and research that is patient-centered and evidence-based, with a foundation in preventive and public health sciences. We are a part of UI Health.